define a dummy with cond()

Dear All, Suppose the data set is

Code:

* Example generated by -dataex-. For more info, type help dataex
clear
input float n int rep78
 1 3
 2 3
 3 .
 4 3
 5 4
 6 3
 7 .
 8 3
 9 3
10 3
11 3
12 2
13 3
14 3
15 4
16 3
17 2
18 2
19 3
20 5
end

My command is

Code:

gen d = cond(rep78>2,1,0)

However, I need `d' to be missing for the 3rd and 7th observations. I wonder the command `cond()' can do this?